Weak cryptographic algorithms can now be disabled in Java SE 7 release. The MD2 Message-Digest Algorithm was disabled by default in Sun PKIX provider and SunJSSE provider.
The MD2 algorithm is a cryptographic hash function developed by Ronald Rivest in 1989, and was published in 1992 as an Informational RFC (RFC 1319).; RFC 6149 moves RFC 1319/MD2 to historic status, "Since its publication, MD2 has been shown to not be collision-free, albeit successful collision attacks for properly implemented MD2 are not that damaging. Successful pre-image and second pre-image attacks against MD2 have been shown."
Although MD2 is no longer considered secure, it remains in use in public key infrastructures as part of certificates generated with MD2 and RSA. An a countermeasure of the vulnerability, Java SE has disabled MD2 algorithm in certification path building and validation.
You may wonder, Java SE has disabled MD2 algorithm in certification path building and validation in the latest…
Prepare the ClientHello Parser
Applications need to implementation their own APIs to parser the client hello message from a plaintext socket. Suppose that an application design the following API to do the work, SSLCapabilities and SSLExplorer.
SSLCapabilities is defined to show the SSL/TLS security capabilities during handshaking, SSLCapabilities can be retrieved by exploring the network data of an SSL/TLS connection via SSLExplorer.explore(ByteBuffer).
* Encapsulates the security capabilities
* of an SSL/TLS connection.
* The security capabilities are the list
* ciphersuites to be…